Electro-optical telecommunications systems and components continue to require improved efficiencies due to rising demands for higher data transmission rates.
In optical communications, optical modulators, such as Mach-Zehnder modulators, may be used to transfer modulated data in electrical (e.g., radio frequency) format onto an optical carrier. Optical Mach-Zehnder interferometer type modulators operate on the principle of interference between two optical waves at a point of recombination near the output port, wherein the optical waves have been divided from a common wave at the modulator's input port. The interference is controlled by a difference between distances traveled by these two optical waves between the points of splitting and recombination. These distances are controlled by varying the optical refractive indices of the two waveguides defining the optical paths or branches between separation and recombination. Of note, it is understood that the distance traveled has a physical distance which is constant and medium induced distance; varying the optical refractive indices varies the medium induced distance.
Capacitance is the primary limiting parameter in carrier depletion modulators which leads to reduced bandwidth and higher power consumption. Thus, strategies to overcome these limitations in optical Mach-Zehnder modulator configurations are needed.